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Construction Corner - Tall towers reach for sustainability

As the drive for sustainability in our highrise buildings becomes more and more important, it's easy to forget that we already know a good deal about how to design and build structures that are tall, energy-efficient and humane.

Korky Koroluk

Just take a look at Manitoba Hydro Place in Winnipeg. It’s been around for three years or so, the people who work there seem to love it and it doesn’t use much energy.

In fact, it is 66 per cent more efficient than the Model National Energy Code for Buildings, consuming a miserly 88 kWh/m2 per year.

Like most sustainable towers that have been built, there has been a lot made of all the technology behind the building’s mechanical systems.

It has all the bells and whistles, the sensors and motors. But, more and more, said Hao Ko, these new buildings can feel “oddly inhuman.”

Ko is senior associate and design director for Gensler, big architecture, planning and consulting firm with a practice that spans the world. He said the problem with many of today’s complex buildings is that they are simply offices, places to work and the occupants aren’t engaged in any way with the building.

Gensler wants to change that, he said, by designing buildings in which people are happy with their surroundings.

He said that we need to broaden the definition of “sustainable” to include the building’s “ability to sustain the human spirit, as well as its performance goals.”

Ko offered Manitoba Hydro Place and the KfW Bank headquarters building in Frankfurt, Germany, as examples of this next generation of sustainable towers.

He expects that the 33-storey glass tower his firm is building in Pittsburgh for PNC Financial, will follow in their footsteps while expanding the notion that an office tower should be a warm, inviting space.

We’re not used to thinking of our office towers that way.

Manitoba Hydro Place, achieves this by clever use of a double skin, which allows the building to “breathe.”

The double skin allows the use of operable windows (when Winnipeg’s winter permits), and an elaborate day-lighting system means the interior is bright with natural light. Occupants can adjust windows and daylighting to suit themselves.

There are ample common spaces where people can meet for lunch with air flowing naturally around them, as if they were sitting on a park bench eating their sandwiches.

The PNC building in Pittsburgh will have what Ko called a “sky garden”—five storeys at the top of the building that will contain conference rooms, open spaces for informal meetings and a glass-walled “outdoor space.”

The building is designed as a series of two-storey “neighbourhoods” with offices on the bottom floor of each, and a common area on the second floor where people can gather informally, either for work or simply for taking a break.

“It’s about bringing people together,” Ko said, “creating spaces that encourage people to have chance encounters.”

Almost all of the building will be lit by daylight, with desk lamps the only auxiliary lighting needed.

The building will have a double-skin façade with a system of automated air vents.

A series of automatic sensors will open up the building for air when the weather is nice.

People will even be able to step out onto a ledge between the two skins if they want more air.

It’s all about giving people control of their personal environment.

Studies have shown, Ko said, that when they can do that, they’re happier, healthier and more productive.

We’ve learned a lot about what people want in their workspaces, thanks largely to the tightly sealed buildings that went up in an earlier drive for energy efficiency.

Now, technology has caught up with what the people say they want, and the new generation of tall towers is beginning to exploit that understanding.